The main objective of peritoneal dialysis is to partially replace the natural kidney function. Peritoneal dialysis (PD) can be used for correcting the following medical disorders:
1. Acute and chronic renal failure
2. Severe water retention
3. Electrolyte disorders and
4. Drug intoxication (acute poisoning)
However, PD is the second dialysis choice to the more efficient Hemodialysis treatment. Hemodialysis is a direct treatment of the blood using an extra-corporeal system with an artificial membrane (kidney), while peritoneal dialysis uses the principles of osmosis and diffusion across the peritoneal membrane to indirectly remove toxic substances from the blood, and thereby correct certain electrolyte and fluid imbalances. The extra-corporeal hemodialysis is used more often when rapid and efficient dialysis is necessary because of excessive hospital patient load and/or severe renal failure or drug intoxication.
Hemodialysis is technically more demanding and more restrictive for the patients than peritoneal dialysis, and those along with other medical reasons have resulted in the steadily increasing use of the simpler peritoneal dialysis (PD).
Although PD was developed long before hemodialysis was introduced, it did not receive attention from most of the clinicians until recently. The current advances in PD have led to an increasing number of patients using peritoneal dialysis. Some of these advances have introduced different PD techniques and others have helped to reduce the peritonitis (infection) rate which is by far the most serious complication associated with PD.
During the last 15 years the advances in PD extended the manual PD from acute therapy only, to chronic therapy. Automated PD was made possible by the introduction of the first proportional PD machines and later by the simpler cycler machines. Because of PD machines, Intermittent Peritoneal Dialysis (IPD) was used for both home and hospital treatments. The Continuous Cyclic Peritoneal Dialysis (CCPD) which is an automated form of Continuous Ambulatory Peritoneal Dialysis (CAPD), has proven that it can reduce the risk of peritonitis. However, since CAPD is a simpler form of home PD, the majority of PD patients are trained on this therapy.
With CAPD the patient manually performs four to six fluid exchanges daily. In between exchanges the patient carries the dialysate in the peritoneal cavity for four or more hours. Of all the PD techniques CAPD has the highest peritonitis rate. Repeated peritonitis may cause scarring of the peritoneal membrane and may reduce membrane permeability. This may lead to a premature termination of PD therapy for the patient. The severity and the frequency of peritonitis have led to a number of technical advances, all intended for use with CAPD, but none of these advances has been shown to significantly reduce the peritonitis rate in any controlled studies. The search continues for a device or technique which will remove this impediment from PD and thereby improve its widespread acceptance.
The recent addition of the "Y" tubing set offers the possibility of peritonitis rate reduction in CAPD. However the complexities and unrefined procedures of the "Y" set have not made its operation friendly to patients. Hence, poor patient compliance, which leads to poor aseptic technique, has masked any great beneficial contribution of the "Y" set to the reduction of the peritonitis rate.
Irrespective of how PD is performed, be it manual PD, IPD, CAPD, CCPD or whatever, there is only one major and critical event that is common to all these procedures: the patient has to be connected to and disconnected from the dialysate source. And that is where the highest risk of infection is understood to originate.